DHW System Imbalance – Short cycling or insufficient hot water

What does DHW System Imbalance mean?

The domestic hot water (DHW) system may experience short cycling of the boiler or fail to provide adequate hot water. This can be due to an undersized DHW tank, an improperly selected pump, or insufficient water flow through the heat exchanger.

• Undersized DHW storage tank
• Incorrect sizing or selection of DHW circulating pump
• Inadequate water flow to the boiler heat exchanger
• Issues with DHW tank temperature sensor verification

Click steps to track your progress.

1. 1

   Review the DHW storage tank capacity to ensure it meets the household's demand.

2. 2

   Have a qualified technician verify the sizing and operation of the DHW circulating pump.

3. 3

   For non-Viessmann DHW tanks, ensure the DHW temperature sensor has been properly verified by an installer.

4. 4

   Consider installing a temperature tempering valve in the DHW supply line as recommended for optimal performance.

5. 5

   Contact a heating contractor to perform accurate calculations for DHW tank coil pressure drop versus boiler pump head.